The present invention related generally to systems and methods for determining dot gain.
There typically exists a discrepancy between a digital dot areaxe2x80x94the size of an ink dot intended to be generated by a printing apparatusxe2x80x94and the actual printed dot area created on the printing media. This can lead to detrimental effects in the quality of the resultant image. For example, a printer or press generally employs a fixed number of inks (for example, 1, 2, 3, 4, 5, 6, or 7 inks) and mixes different ink dots having different dot areas to achieve many more colors. If the printed dot areas are incorrect, the resultant colors or images appear incorrect.
In order to correct for this discrepancy, a dot gain table is typically used to relate printed dot area to digital dot area. To populate this table, one or more pages or swatches are printed using known digital dot areas for each color or ink. The printed dots are then measured. In this manner, a dot gain table is generated, with the points between measured points being interpolated from the measured data. In operation, the printer or press uses the measured and interpolated dot gain table to print the printed dot area desired. To keep up with drift in the press, this process needs to be performed as often as possible, and therefore requires a large number of pages for each calibration.
An embodiment of the present invention provides a method for determining dot gain. A state parameter is measured and provided as an input to a statistical learning system. Using the statistical learning system, a plurality of printed dot areas, each corresponding to a specified digital dot area, are estimated.
Another embodiment of the present invention provides a method for printing. A specified printed dot area is received, and a state parameter is input. A digital dot area corresponding to the specified printed dot area is determined using a dot gain lookup table corresponding to the input state parameter. A control signal corresponding to the determined digital dot area is generated.